422 
with the centuries and spread into the 
neighboring domain of chemistry, where it 
vitalized the dynamic interpretation of 
chemic union and aided in producing Avo- 
gadro’s law, which, according to Cooke, 
‘holds the same place in chemistry that the 
law of gravitation does in astronomy ”* and 
forms the basis of what has justly been 
called the New Chemistry. This law, like 
all others in science, afforded a means of 
prevision, or of presaging the unknown in 
terms of the known, and thus of testing its 
own validity ; and as test followed test the 
idea of orderly succession grew until, with 
the aid of refined observation and the guid- 
ance of special experiment, it matured in 
the doctrine of the persistence of motion, 
the keynote of modern science. Here was 
a vantage point from which the astronomer 
was enabled to study the celestial bodies, 
especially our own sun, not merely as 
masses, but as chemical and physical as- 
semblages ; and so arose the line of research 
sometimes called celestial physics, but de- 
fined and dignified by Langley as the New 
Astronomy,{ which has already afforded a 
means of analyzing the constituents and 
measuring the movements of several among 
the myriads of other suns than ours. True, 
each of these strides in the advance of 
physical science represents progressive ap- 
preciation of cosmical forces; yet still more 
fully do they represent progress in recog- 
nizing orderly sequence and causal succes- 
sion in the movements of molar and molec- 
ular bodies. 
Borrowing from physical science trench- 
ant ideas concerning force and succession, 
even the earlier biologists analyzed the 
mechanism of living things and slowly 
stripped away the primitive panoply of 
mystery or divinity in which the infantile 
imagination, whether of men or races, has 
*The New Chemistry’ (International Scientific 
Series, VI.), 1875, page 13. 
{ ‘The New Astronomy,’ 1888, chapter 1. 
SCIENCE. 
[N. 8. Vou. VI. No. 142. 
always enveiled vitality. Lamarck was one 
of the first to extend the idea of orderly 
succession to organisms, and, although his 
special hypothesis of development has fallen 
into abeyance, it has features which anthro- 
pologists do well to remember; then came 
patient Darwin and doughty Huxley and 
studious Spencer with the definite doctrine 
of organic evolution, which spread from 
man to man and from land to land, produc- 
ing the greatest and quickest intellectual 
revolution in the history of the world. Al- 
beit: revolutionary, the Darwinian doctrine 
was but the biotic complement of the phys- 
ical doctrine of the persistence of motion, 
and the two doctrines are twin buttresses 
on which the symmetric structure of modern 
science is supported. Through the latter 
doctrine the world and the things thereof 
were transfigured in a new beauty and per- 
fection, the universe was invested with a 
new glory, and the narrow notion of breaks 
in the uniform course of nature by special 
fiat lost hold on the scientific mind forever. 
It chanced that while the ferment of evo- 
lution was still fresh a trio of American 
geologists (Powell, followed by Gilbert 
and Dutton) entered the inspiring region 
traversed by Colorado Canyon, and be- 
fore their work was done the germ of 
geomorphy, or the New Geology, was 
planted. It was realized more clearly than 
ever before that the hills are not everlast- 
ing but everchanging, and that the features 
of every landscape tell an eloquent tale of 
continental evolution in which competent 
cause and commensurate effect follow ever 
in ceaseless succession through the eons of 
earth-making. The task of the geologist is 
not ended, indeed is only well begun; yet 
here as in other sciences the reign of law is 
realized, and the day of appeal to chance is 
past. 
When Huxley sought ‘Man’s Place in 
Nature,** and still more when Darwin 
* First publication in 1863. 
